Virginia Governor Ralph Northam (D) did not resign Saturday, saying he believes he is not one of the people in a 1984 medical school yearbook photo in which one person is dressed in blackface and another is wearing a full Ku Klux Klan costume.

Northam called a news conference to fight the allegations against him.

In a statement delivered in front of members of the media and a live television audience, Northam said he believes that neither of the people that appear in the photo is him and asks Virginians for the opportunity to "earn your forgiveness."

"I believe now and then that I am not either of the people in this photo," he said.

He said he did not know about the photos placed on his yearbook page and was appalled when he saw the images in his yearbook. Northam said he did not buy a yearbook and knew nothing about the photos until they were shown to him.

The governor admitted that he had darkened his face with shoe polish in the 1980s while dressing up like Michael Jackson at a dance contest in Texas when he was in the US Army.

Northam is facing mounting pressure from within his own party to resign.

On Friday, the Virginia Legislative Black Caucus said in a statement that the yearbook photos "rip the scabs of an excruciatingly painful history and are a piercing reminder of this nation's sins. Those who would excuse the pictures are just as culpable."

The group said it felt betrayed by Friday's revelation and said the legacy of "slavery, racism, and Jim Crow has been an albatross around the necks of African Americans for over 400 years."

Northam first issued an apology in a written statement, calling the costume he wore "clearly racist and offensive," but he didn't say which one he had worn.

Later, he issued a video statement saying he was he was "deeply sorry" but still committed to serving the "remainder of my term."

"I accept responsibility for my past actions and I am ready to do the hard work of regaining your trust," Northam said.

If Northam resigns, current Lt. Gov. Justin Fairfax, 39, a Democrat who is only the second African American to win statewide office in Virginia, would be the next governor. He would also be only the second African-American to serve as the Commonwealth's chief executive. Northam's term is set to end in 2022.

Before becoming lieutenant governor, Fairfax served as an assistant United States attorney for the Eastern District of Virginia in the major crimes and narcotics unit of the Alexandria division. He graduated from Duke University with a degree in public policy studies in 2000 and earned his law degree at Columbia Law School.

A descendant of slaves, Fairfax was holding his great-great-great-grandfather's manumission papers from 1798 in the breast pocket of his coat when he was sworn in as lieutenant governor last year, according to Virginia television station NBC 12.

Black lawmakers said they met with the governor Friday evening and said in a statement they appreciate his service.

"But given what was revealed today, it is clear that he can no longer effectively serve as governor," the Virginia Legislative Black Caucus said, "It is time for him to resign so that Virginia can begin the process of healing."

Derrick Johnson, NAACP president, and CEO released a statement Saturday saying the organization stands by its call for Virginia's governor to resign.

"We are deeply disappointed in Gov. Ralph Northam decision to not resign today. His failure to take accountability for his actions is sickening. He says he used shoe polish on his face to mimic Michael Jackson, yet denies he ever used blackface. This is unacceptable for any leader," Johnson said in the statement. "He contradicts his earlier decision to admit responsibility to now say he had nothing to do with the photo. Implicit bias is bias, and it's clear that someone who cannot distinguish from using shoe polish on his face to imitate a Black person from blackface, clearly suffers from this or is delusional."

"This image is an example of the historical effects of institutional racism and the lack of awareness of the discrimination against Black people," the statement continued. "Racism of any kind cannot be excused nor overlooked. We stand by our call for his resignation. He will now have to answer to his constituents in Virginia who will find it difficult to make peace with his choice. "

Several potential Democratic presidential candidates including Sens. Elizabeth Warren of Massachusetts and Kirsten Gillibrand of New York and former Maryland Rep. John Delaney, also called on Northam to resign.

Tom Perez, chairman of the Democratic National Committee, released a statement that said Northam no longer has the public trust and should step down.

“His past actions are completely antithetical to everything the Democratic Party stands for,” Perez said. “Virginians and people across the country deserve better from their leaders, and it is clear that Ralph Northam has lost their trust and his ability to govern.”

Former Vice President Joe Biden and Sen. Bernie Sanders of Vermont, both potential 2020 presidential contenders, weighed in on Twitter on Saturday, saying it was time for Northam to hand over to Lt. Gov. Justin Fairfax.

Biden said Fairfax, a Democrat, “is the leader Virginia needs now.”

Northam, a pediatric neurologist, came under fire last week from pro-life advocates and Republican lawmakers after he said he backed a bill allowing abortion up until shortly before birth. Critics said his remarks supported infanticide, which Northam denied.